As i said in an earlier version of your proposal, i don't agree. I somehow feel upset you decided to start another thread with this and discarded the no's you received and expect us to repeat ourselves.
I will not try to repeat myself, if i do, it's because the reasons are the same.
Therefore, to start, some reasons to no:
1. "When spying on a city, you have the option of keeping a spy in the city for as long as you like, providing a new spy report whenever you need it. However, to do this you must give a spy more than have of the silver in you targets cave. For example, if my opponent has 10000 silver in his/her cave, for my spy to stay there I must give it over 5000 silver everyday for it to remain unseen. If I am out of silver for any reason, I have the option to recall my spy before the day is over. If I give the spy coins but do not give it more than half, the spy is discovered and your cave loses the amount of silver in your target's cave."
So, we need to guess the silver amount... ok, when is the "discover" process made so i "give" the spy money? 0:00? 12:00? 15:45? Server time or GMT+0? What do you mean "give"? Do i send silver to somewhere? stack it in a new "long distance cave system"? And for what purpose as i can send spies whenever i choose?
Why would this complicated thing be implemented when everyone can send spies whenever they chose?
"Now we're getting to the juicy parts.". And indeed we are.
2. "You can declare war on another alliance, giving a more tactical feel to war, and make sure your enemy is punished for losing."
Ok, let's see. Alliance A plans 2 attack B. They prepare all their attack forces make the plan and they declare war for let's say 10.000 ABP. They send the war invitation and wait for B to accept. Now B, not being noobs, they know what's up, so they do the same, prepare the attacking force, make a plan. but not accept the war invitation right away. Why, because they're not stupid. So they wait let's say 12 hours so they are ready for launching at the time T. and quickly 1 minute before time T, they accept the war declaration, then send all their attacks. Alliance A falls under their own scheme because B gets the ABP in the first hours, before A even knew what happened. Case closed for A.
Ok, you will say A will only make "serious" war declaration. By that meaning only big ABP, or other conditions are met. But that's like marriage, A will ask to be in a "relationship" with B for maybe a long long time. Imagine C, asked by A to be their ally, involved in a long long thing they didn't even asked. Probably they'll go no way.
Maybe, just maybe, alliances do switch sides. Don't tell me it didn't happened before. But won't happen again as they'll be stuck in a war for as long it will take place. What misery....
My point is: lots of changes, lots of problems but for what reason?
3. Here comes the reason. Punishments and gains. Or gains and punishments.
"When you win a war, your opponent needs some sort of punishment for their loss. For a punishment, you can choose one of the following:
>Forced Diplomacy- The losing alliance(s) cannot attack a winner alliance for 1 week, and cannot declare war for 1 month.
>City Takeover- The losing alliance cannot conquer a city for 3 days, and cannot colonize for 2 days.
>Troop Limit- The soldier population of the losing alliance(s) cities is at a maximum of 700."
Forced Diplomacy - Ok, so alliance B, loosers, are now punished to not fight back. Lovely. Usually people do want to fight back, but no-no, they will not be able to do so. Because a message like "you cannot attack this alliance, they're the bosses, they owned you, now you sit in your place and eat your pain in silence. you looser." will pop up? Don' like this.
City Takeover - Better, they lost and now they can't even expand for a while? Shot in the leg they are for playing a game.
Troop limited - now this is interesting. They can't even rebuild. Great, now A can attack them without them being able to actually defend.
Should an alliance accept the eventuality of punishments? Yes, if they want to risk being their last presence on the game's world...
As said previously to the initial proposal of this, making war is not a "Gentlemen agreement". War tends to create angry mob, dislike, resentiments. And adding the "gentlemen" part doesn't quite suits war.
4. Abuse prevention. Is there really none?
Ok, let's see A and B alliances are palls. You know, really good friendly alliance. And A and B have ghost players. THey decide they DO want to take over their own dead weight. Why not make some great bp from this? So, A and B decide to create a war for bonuses. Yep, A send their dead list to B and B sends their dead list to A. They create the war declaration based on let's say 150.000 bp. Then, they start attacking dead players. They get 50% more abp attacking the other alliance dead players than they normally would by attacking their own players. They also keep the score internally, how many abp each one has (in order to not end the war before each get the most possible), and what towns are cleared. The war ends, offcourse they didn't set any punishments, they're palls and palls don't do that! And now, they killed troops worth of 100.000 bp but got 150.000 because of the "war declaration benefits". Satisfied, each alliance now sends the list of the cleared towns to the other alliance, and internally take over the dead players.
Rinse and repeat. Each time A and B have dead players or want some free bp, they just "create a war" and abuse the world as they please.
Prevention? None.
Abuse? A lot.
Having said the above, i don't want 2 write more. My fingers hurt. Let's not ruin the game with this, at least in current form. Please.